21120221222121 has 16 divisors (see below), whose sum is σ = 32968150201728. Its totient is φ = 11774339356800.

The previous prime is 21120221222117. The next prime is 21120221222123. The reversal of 21120221222121 is 12122212202112.

It is not a de Polignac number, because 21120221222121 - 2² = 21120221222117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21120221222123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12264935970 + ... + 12264937691.

It is an arithmetic number, because the mean of its divisors is an integer number (2060509387608).

Almost surely, 2^{21120221222121} is an apocalyptic number.

21120221222121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21120221222121 is a deficient number, since it is larger than the sum of its proper divisors (11847928979607).

21120221222121 is a wasteful number, since it uses less digits than its factorization.

21120221222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24529873712.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21120221222121 its reverse (12122212202112), we get a palindrome (33242433424233).

The spelling of 21120221222121 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".